1. Field of the Invention
The present invention relates to a light source system, and more particularly, to a light source system for use in a stereoscopic projection apparatus.
2. Descriptions of the Related Art
Conventional light source systems for use in stereoscopic projection apparatuses mostly adopt a color wheel or two liquid crystal switches for light splitting. In either method, a light beam generated by such a light source system can be transformed and divided into a left-eye and a right-eye view-angle image. Then, the left-eye and the right-eye view-angle images are projected by a plurality of digital module devices to the visual fields of a viewer. Hereinbelow, basic design principles and bottlenecks of the two kinds of light source systems will be described briefly.
First, a light source system adopting a color wheel as a light splitting element will be described. For example, an RGB color wheel must have at least six color filtering regions, with the left eye and the right eye corresponding to three color filtering regions (i.e., a red filtering region, a green filtering region and a blue filtering region) respectively. In practical operation, the viewer can watch a stereoscopic image by simply wearing a pair of passive eyeglasses. However, this arrangement has a shortcoming in that because the color wheel must cover at least six large-area filtering regions for an incident light beam to be incident on the color filter at a small angle, it is difficult to reduce the volume of the color wheel. In other words, this makes it difficult to miniaturize the stereoscopic projection light source system.
Next, a light source system that adopts liquid crystal switches as a light splitting element will be described. The liquid crystal switches need not to be actuated by a mechanism, so mechanical wearing can be avoided. However, the liquid crystal switches must operate at a precision higher than that of the color wheel. Therefore, the problem of synchronism must be particularly considered in the design; otherwise, it will be difficult for the viewer to see a stereoscopic image or the quality of the stereoscopic image seen by the viewer will become poor. Briefly, the light source system adopting liquid crystal switches is complex and it is difficult to lower the cost thereof.
Accordingly, there is a need existing in the art to design a light source system that can be used with a pair of passive glasses, improve the light utilization factor, and have a low cost, a simplified optical arrangement, a high resolution, a miniaturized volume or increased brightness.